As LSI circuits are increasing in density, the line width of circuits of semiconductor devices is becoming finer. Examples of methods of producing an exposure mask (also called a reticle that is used in a stepper or a scanner) to be used to form a circuit pattern for such a semiconductor device include an electron beam writing technique with high resolution.
As an electron beam writing apparatus, a writing apparatus using multiple beams has been developed as a replacement for an existing single beam writing apparatus that deflects one beam and irradiates a necessary location on a substrate with the beam. By using multiple beams, irradiation is possible with more beams than in the case where writing is performed using one electron beam, thus resulting in a significantly improved throughput. In a multibeam writing apparatus, for example, an electron beam emitted from an electron gun is caused to pass through an aperture member having a plurality of holes to form multiple beams, blanking control is performed on each beam at a blanking aperture array, a beam that is not blocked is reduced using an optical system, and a substrate placed on a movable stage is irradiated with the beam.
Checking of whether, for each beam, a beam current or focus has a desired value, whether ON/OFF control can be performed at the blanking aperture array, and so on is desired for the multibeam writing apparatus. Hitherto, beam checking has been performed by scanning a Faraday cup while the beam to be set to ON at the blanking aperture array is switched on a one-by-one basis. However, multiple beams are a number of beams (for example, about 260 thousand beams), and there is a problem in that this checking requires a long period of time if this checking is repeatedly performed for the number of beams.